Model Output Discussion 12z 10/05/13

[Frosty.]

Several cm's of snow tonight on the mountains in wales and wet snow across some lower ground in east wales and the west midlands but mostly it's torrential rain with local flooding, as much as 50mm locally, generally 20-40mm in the frontal zone, eventually clearing by tomorrow morning with heavy rain moving up into eastern scotland, sunshine and showers for most areas for the rest of this week but a very wet and very cool and windy spell for most of the uk by the weekend.

Edited May 14, 2013 by Frosty039

[Radiating Dendrite]

wet and cold..and windy

Great.........so I am unlikely to see any play?

Can we have Global Warming back please!!

[Frosty.]

Great.........so I am unlikely to see any play?

Can we have Global Warming back please!!

There will be some play on thursday and friday between the heavy showers but the weekend looks a washout, not only for the south and east but for most of the uk with a big low covering the uk, the atlantic/azores high should settle the weather down from the northwest by early next week.

Edited May 14, 2013 by Frosty039

[Gibby]

Hi folks. Here's my morning account on the midnight output taken from GFS, UKMO, GEM, NAVGEM and ECM for today Tuesday May 14th 2013.

All models illustrate a cool and unsettled spell for the remainder of the week as low pressure continues to circulate around or over the UK for the next 4-5 days at least. This means within a broad showery pattern with some heavy and thundery ones scattered about there will be some longer spells of rain too, notably today across the South and across the East too tonight, Friday and Saturday. It will be on the cool side at all times but notably so under the precipitation though with some compensatory sunny intervals in between when it will feel relatively pleasant.

GFS then leads us out of the weekend and into the new working week with a NW/SE split developing with the best of the dry and pleasant conditions reserved for the NW for a change with some pleasant sunny spells here while Southern and Eastern England are prone to showers in association with Low pressure continuing to dominate areas to the South of the UK, edging further North at times. Gradually in this run the showery trough to the South extends back North through the following week putting all areas at risk of some rain or showers with average temperatures likely in relatively light winds. The end of the run this morning show quite complex synoptics but in essence Low pressure will be inching closer into the UK from the West maintaining the unsettled pattern with occasional rainfall a risk for all in average temperatures at best.

The GFS Ensembles indicate a warming to above average uppers after the coming week's coolness. The problem is will this be translated to the surface and with all the unsettled and flabby Low pressure areas that look likely to persist close to the UK, especially the South I think nearer to normal temperatures are more likely to be translated at the surface coupled with rain at times. These ensembles do provide good growing prospects though for farmers and growers as we lift out of the cold pattern.

The Jet Stream shows the UK trough forming as we speak promoting the rapid growth of today's depression as it moves East. The trough in the flow lasts for several days before the Jet develops a split flow again next week with both arms relatively weak. The southern portion will be blowing across the Meditteranean while the Northern arm is way up over Iceland to Northern Norway.

UKMO this morning has Low pressure over the English Channel next Monday with unsettled weather continuing for all following a fairly grotty weekend. There would be showers or longer spells of rain, especially in the South and it would continue to feel none to warm in the rain. The far NW will see the best of the dry and sunnier interludes and it could well be warmer then most in shelter from the East.

GEM today shows a similar 144hr chart to UKMO which then moves on to show the Low filling and moving away with pressure building strongly down from the NW so that by Day 10 all areas have become dry and warm with sunny spells under a strong ridge from the Azores.

NAVGEM is poor though in comparison maintaining Low pressure in control of the UK weather out to the end of it's run with further days of showers and sunny intervals with the odd more prolonged spell of rain too for good measure as Low pressure on Day 8 remains close to the East coast.

ECM finally does show improvements as we move out of the weekend and into next week as it attempts to throw something of a ridge in from the Atlantic High. This would mean a reduction (though not total) in showers as we move into next week with a slack flow from the North or NW. Alas it doesn't look like lasting though, especially in the North as Low pressure is developing to the NW to bring cloud and rain into these parts soon after the term of the run with the synoptic orientation suggesting that this would extend SE to other areas too in the days that followed.

In Summary we remain locked in a relatively unsettled and showery pattern of weather for quite a while yet. It does look as though the very cool conditions we are currently enduring under the rain and showers will slowly lift away lover the coming weekend bringing temperatures at the surface up to what we would normally expect at this time of year and maybe above in any sunshine. However removing the unsettled weather is a tougher nut to crack as the Atlantic High remains stubbornly anchored out West maintaining the risk of the showery trough over NW Europe to persist and perhaps get reinforced at times. GEM does offer a crumb of comfort though and being that it's 144hr chart is closely replicated by UKMO's then I hold on to the hope that maybe UKMO would follow suit to GEM's conclusion if it ran until Day 10. So there you have it I'll be back later to disect the 12zs.

[johnholmes]

Pretty well summed up there Gibby. Our resident trough is ruling the weather for sure. Some high rainfall totals today and again on Saturday with subsequent run off problems. Snow also for some hilly areas tonight chiefly the Peak and Pennine areas but some hills further south may get some very wet snow for a time.

Beyond that and the 500mb anomaly charts are probably hinting at a change from the pattern they have kept for the last 6-7 days. This seems to suggest that an upper ridge will begin to take over about 6-10 days from now with the trough fading away. Not clear just yet though. Over the last couple of issues all 3 have started to show changes. When this happens it can sometimes simply be a hiccup in their pattern. Their equivalent of the run to run changes in the synoptic models and it only happens on a much lower scale than the synoptic shifts. Or it is the start of a pattern change. I tend to think in this instance it is the latter. They are not showing all that similar patterns so don’t take too much notice in the link below of the positioning of either upper features or the anomalies. But I think they do indicate this shift starting to occur from trough dominated to ridge dominated. The actual pattern yet to settle down so trying to work out the surface pattern beneath that is even more of a problem.

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

This will become clearer over the next 48 hours and should allow some idea of what surface pattern we may be under by month end.

[Summer Sun]

Although never spectacularly warm the ECM ensembles continues to show high pressure build next week once the potential nasty low on Sunday heads back into mainland Europe

 

 

The GFS ensemble shows a clear warm up from the 22nd onwards precipitation alo

 

 

The ECM Birmingham monthly ensemble continues to look better as well running just below average which is better than a few weeks back when it was well below average

 

[Frosty.]

The Ecm 00z op run is actually pretty good once we get past that damp squib of a weekend, the trough responsible for the poor weekend weather slips south and high pressure begins to fill the void to the north and west, we are briefly in a col but the azores/atlantic high builds strongly to the west/northwest and it currently looks as though northwest britain could be the first to have a relatively fine and slightly warmer spell next week, the fine weather spreading to all areas through next week and the ridge holds across the uk until later next week, so a marked improvement after the weekend is shown on the ecm 00z, the ecm 00z ensemble mean is also trending towards a fine and warmer further outlook, as is the gefs 00z mean which I posted charts for earlier.

[Peejayem]

purga...why are you so obsessed with northern blocking....its all you ever seem to talk about!

[SnowObsessor90]

Well this latest GFS run finally does the type of thing we'd like to see as we close in on the start of summer, now if only it could be brought into the reliable time frame.

[Frosty.]

The Gfs 06z shows high pressure building strongly to the west and then the north of the uk, eventually migrating away northeastwards but for northern and western britain, a fine and pleasantly warm outlook for most of next week with lots of sunshine, it's looking like more of a struggle further south with low pressure over southern britain which is very reluctant to give ground but there is an improvement for all parts of the uk  during next week on this run with warmer temperatures and at least some dry and sunny weather but it currently looks like n.ireland and scotland are in for their best spell of weather of the spring so far, but southern britain slow to improve although the risk of showers does fade during next week, even in the south as pressure tries to rise, the biggest improvement in the south next week will probably be the temperatures, compared to how cold the weekend, especially saturday due to the persistent rain and NE'ly winds.

[Frosty.]

At the same time there is no guarantee the met office are right anyone remember there failed summer forecast a few years back?

removed my silly comment.

Edited May 14, 2013 by Frosty039

[johnholmes]

good fun Met O bashing but why not post in the correct thread=summer, Met Office 6-15 and 16-30 etc more appropriate than in here or am I talking rubbish?

Lots to discuss in the relatively near time frame with later today into Wednesday and Saturday prime examples, see various model outputs and Fax charts.

Compare the 3 main models on Net Wx basic chart area to see how they deal with today/Wednesday and Saturday.

[Frosty.]

good fun Met O bashing but why not post in the correct thread=summer, Met Office 6-15 and 16-30 etc more appropriate than in here or am I talking rubbish?

Lots to discuss in the relatively near time frame with later today into Wednesday and Saturday prime examples, see various model outputs and Fax charts.

Compare the 3 main models on Net Wx basic chart area to see how they deal with today/Wednesday and Saturday.

I was just having a joke John, just a silly comment from me replying to another met office comment, I have tons of respect for the difficult job the uk met office do..

Edited May 14, 2013 by Frosty039

[Frosty.]

GEM 00z shows a gradually improving outlook next week, towards the end of the week it looks settled and warm with the azores/atlantic high in control.

 

The GEFS 06z mean continues to show the azores high having a significant impact on our weather from next week and especially beyond, it also looks warmer next week with temps in the 16-20c range.

[legritter]

We have plenty to keep us very interested over the coming days a weather watchers dream i would say .todays action i would put at a very high levell of Adrenaline for some of us and this weekend could prove just as action packed.so met office FAX very important as for finer detail .it does look from todays charts and data that high pressure could eventually take control but all is calculated in an ever changing complicated Jigsaw ,and as iv said before put the jigsaw together with all your highs and lows and get it right then place the completed puzzle on to the map ,this is the critical part ,so current thinking by some is high pressure to our north or n/east low to our south, but its that critical placement that will determine our weather .although i love action weather it would be nice for severall weeks of warmish summary weather .i will catch up later after tonights modell runs cheers 

[Frosty.]

Those graphics show higher than usual pressure for the north and lower for the south, yet rainfall is above average for all areas?

Yes it basically covers all bases, the uk seems to fall inbetween both weather types so a mixture of high and low pressure, in other words, a typical british summer. As for the latest met office update, it indicates the north and west of the uk will have the best of it but it's not describing any anticyclonic weather next week, even in the n and w where the 00z-06z op runs are showing the azores/atlantic high covering scotland and northern ireland next week, met office sounds unsettled for all, for most of the time.

[shedhead]

I think a fair bit more water will have to flow under the bridge (as well as fall from the sky) before confidence in the overall evolution for next week improves, let alone the period beyond that. Clearly there have been signs of a pressure rise from the SW later next week across recent runs, especially on ECM, but I don't think we can dust off the barbecues again quite yet. Even if the improved pattern does transpire it's hard to see any genuine warmth developing, but I suppose it's all relative and compared with todays single digit maxima for many even the mid teens will feel a good deal more agreeable.

Edited May 14, 2013 by shedhead

[Purga]

purga...why are you so obsessed with northern blocking....its all you ever seem to talk about!

A - I am NOT obsessed with northern blocking

B - It is NOT ALL I ever talk about

 

As a matter of fact, there has been a considerable amount of northern blocking over the last several years in comparison to former times and as a significant feature I am interested in it but not 'obsessed', so why shouldn't I be?

Edited May 14, 2013 by Purga

[phil nw.]

All posts related to Matt Hugo`s tweet about Summer prospects have been moved to- would you believe- the Summer thread over here

http://forum.netweather.tv/topic/76293-summer-2013/

 

Let`s confine posts on here to talk around the current model outputs please folks-thanks.

[Zenarcher]

On Wednesday a low around 988mb will move across England bringing widespread unsettled weather to many parts of the UK. From 1am to 1pm a heavy band of rain will move across England and Eastern Scotland meanwhile elsewhere will be cloudy with showers. For the rest of the afternoon as the heavy band of rain moves around the far Northern Scottish isles across the rest of the UK it will be mainly partly cloudy with showers, Ireland, Wales and SW England look to be the driest and sunniest. At 7pm it will be cloudy but dry for most apart from England and Wales where it will be clear and sunny and after a wet morning it will be a nice way to end the day. Overnight into the early hours of Thursday staying cloudy with showers pushing in from the West over Ireland. Gale force winds are likely on Wednesday mainly in the West around 35mph. Temperatures in general still on the cold side with only the far south of England getting into the low teens.

 

For Thursday partly cloudy with sunny spells and showers for all of the UK overall it should be sunnier than Wednesday. The wind will be very calm and temperatures still showing no signs of warmth.

 

Friday cloudy with a few showers creeping in from the West and moving across the country. Wind still calm but coming from the North so it will be cold especially in the North.

 

The weekend is unclear at the moment but the 06z GFS had a deep low moving over England and Wales bringing very heavy rain and gale to severe gale force winds. The ECM does show a low but it moves more up North to Scotland and slightly weaker and UKMO has it as well and agrees with the GFS on the positioning and track but has it not as deep.

 

On the longer term outlook for warm weather I can't see any sign of it soon but I expect our chances might get better during the last week of May and into early June.

[Summer Sun]

GFS has shifted Sundays low to the SW of England now quite a shift from its original position over Germany a few days back

 

 

UKMO has backtracked as well the low is no where near as deep now thankfully

 

12z left 00z right

 

Edited May 14, 2013 by Gavin.

[Summer Sun]

UKMO is now jumping aboard the high pressure train Monday see's the high slowly building in from the west

 

 

GFS also builds pressure in from the west but unlike UKMO GFS has a 1005mb low pressure system to the SW of the UK

 

 

 

 

 

[Frosty.]

The Gfs 12z shows an improvement by sunday as the nasty trough which ruins saturday sinks southwest and high pressure builds to the north, sunday looks a lot warmer than saturday with a drier brighter day in the southeast and for most of scotland, the rain slowly becoming more confined to the southwest later. A strong ridge building northeastwards from the azores/atlantic anticyclone brings a big improvement into next week with warmer and sunnier weather extending south and east, it becomes much better early next week with pressure rising to the northeast and the southwest, it's a much better run than the 6z for all areas. Tuesday is warm and humid with sunny periods but with isolated heavy showers breaking out. By midweek it's still fairly warm with sunshine and heavy showers and pressure is falling by then. Thursday looks like trending cooler and more unsettled, especially in the north but high pressure  builds strongly to the west of the uk. By friday it's getting better with a strong atlantic ridge pushing into the uk with temperatures slowly recovering and drier weather returning from the west. The weather then remains fine and pleasantly warm for a few days but towards the end of the run it becomes more unsettled & cooler again. Overall, this is a much better run than the 00z and 06z with warm and fairly settled weather dominating for long periods beyond this weekend, especially in the north & west, still an ongoing risk of showers in the south & east but warm sunny spells too.

Edited May 14, 2013 by Frosty039

[weather_it_will]

GFS continues the trend of of pushing any chance warm and settled weather out the way.

The ensembles have been hinting at this beyond the reliable time for a couple of runs at least,

with low pressure continuing to push in from the north.

If you look at the ensembles mean, it is clear the temperatures flatten out beyond day 8.

There is some signs of a slight warm up near the end of May for London and the south east.

For most of the UK outside of the SE, the outlook does not look that great, with at best average temperatures.

Maybe the odd warmer day here and there, but does not look very dry!

Edited May 14, 2013 by Hot Wet Windy Cold No Snow

[Frosty.]

The good news about the GEFS 12z mean is that pressure looks like becoming generally higher across the uk after the weekend with a fairly slack looking pressure pattern with 1020mb or thereabouts being the general figure, sometimes a little higher or lower than that but it also looks much warmer by early next week following the potentially cold and wet saturday, by sunday it's an improving picture for most areas, especially for northern and western parts of the uk with sunny spells and lighter winds with temperatures recovering well. Most of next week looks at least pleasantly warm and some inland areas will be warm with long sunny spells but there will continue to be scattered showers which could again be heavy with hail and thunder but relatively much warmer than this week with variable temperatures between 16 and 22c.